The Magnetic Resonance angiography (MRA) of supraaortic vessels is essential for the etiologic of stroke. However, the techniques usually used provide only static evaluation (degree of stenosis, occlusion) but not dynamic. An ultra-fast 3D MRA originally developed for the cardiac imaging, k-t blast (Broad-use Linear Acquisition Speed-up Technique) could be used to review the supraaortic vessels. This MRA offers the following advantages: short acquisition time, wide spatial coverage (of the thoracic aorta to the distal encephalic arteries), 3D spatial resolution and high temporal resolution. These qualities are even more optimal with a high magnetic field (3T). The high temporal resolution is interesting because it provides to repeat a volume every eight seconds and thus to have a dynamic evaluation of vascular filling and to assess the vascular supply of the infarcted territory. This sequence is classified as a 4D MRA.

Inclusion Criteria:

• Men and women over 18 years
• Eligibility for intravenous thrombolytic treatment (National Institute of Neurological Disorders and Stroke criteria)
• Permanent ischemic stroke confirm with encephalic MRI (Magnetic Resonance Imaging)
• Patient able of accepting protocol information
• Patient who received information about the protocol and had not expressed its opposition to participate

Exclusion Criteria:

• Pacemaker
• Surgical ferromagnetic clips
• Cochlear implants
• Intraocular metallic foreign body
• Iron implants or objects likely to concentrate the Radio Frequency field
• Claustrophobia
• Known intolerance to contrast media (DOTAREM)
• Pregnant women (Beta Human Chorionic gonadotrophin performed for biological assessment of thrombolysis)
• Patient with severe kidney with Glomerular Filtration rate < 30 ml/min
• Persons subject to major legal protection (safeguarding justice, guardianship, trusteeship), persons deprived of liberty

Patients with acute ischemic stroke